1. Field of the Invention
This invention relates to valves which require a gas-tight seal such as surface valves used on oil and gas wells, and more particularly, to such a valve having pressure energized seals and a gear actuation mechanism for opening and closing the valve.
2. Description Of The Prior Art
Surface valves utilized on oil and gas wells must be as gas-tight as possible to minimize the potential hazard of gas leakage. There are a number of prior art types of valves used, such as rotating plug valves, ball valves, gate valves, etc. Probably, the most commonly used valves are gate valves.
A problem with existing gate valve designs is that they have a relatively large number of parts and are somewhat expensive to manufacture. Also, they are not easily redressed after the valve has been subjected to wear, and they are not particularly well adapted to have components thereof fabricated from hard materials, such as ceramics or tungsten carbide materials.
The present invention provides a rotating valve with fewer number of parts than the typical gate valve and which is relatively inexpensive to manufacture The valve of the present invention is also easily, redressed and components thereof may be easily fabricated from ceramic or tungsten carbide materials.